Which Drill Bits Should Be Used for Extremely Hard Metals?

Drilling iron is not simple, the same goes for steel. That's why you need drill bits for extremely hard metals that are able to withstand the stresses of a work that is always useful, and not only when organizing a worker's toolbox or for professional carpentry work. Having the ability to make a quality hole, precise and without burrs, is important.

But it's a need that concerns everyone. Even those who need to set up a garage to take care of their car or simply do home maintenance work. The truth: without the right drill bits you risk getting mediocre work. And damaging the equipment. Here are the characteristics to observe if you need drill bits to use for extremely hard metals.

Material of drill bits for difficult drilling

First aspect to consider when listing the best drill bits for drilling iron and stainless steel: which material should we choose? How should these tools be composed to avoid damage and burred holes? If you need to work on special steels like those with nickel or manganese it is advisable to always use bits in HSS, high speed steel, but with cobalt content.

This makes the drill bit more resistant, suitable for drilling at high speeds on hard metals. You will find HSS Co5 and 8 drill bits, namely the percentage of cobalt present in the mill: they are even more resistant and suitable for drilling extremely hard metals and special steels.

The plate of the drill bit for treated materials

To remember that some models also have a different combination for the plate (initial part of the drill bit): the best options are in hard metal K20, a sintered tungsten carbide bound with cobalt contents to use when high abrasion resistance is required. In fact, these drill bits - like the 01093 by Krino - are used mainly for drilling treated steels.

Shape and structure of a drill bit for metal

A technical difference that allows us to have drill bits suitable for drilling extremely hard metals: the method with which the structure was created. The rolled solutions provide for a modeling of a metal bar that is heated and elongated to create the drill bit. Ground ones instead start from a structure that is then worked, without any elongation process.

This means that the last alternative, that of ground drill bits, is certainly suitable for superior precision of the hole. Without forgetting that they are more resistant, especially if you choose ground cobalt drill bits as suggested in the Cutting Tools article. Usually, for this type of work, the use of S drill bits, point angle of about 130°, is provided for, while W drill bits are suitable for drilling particular work such as drilling austenitic steels. One of the best conditions?

It is the Speedmaster by Krino, helical cylindrical solutions ground with double cone with self-centering micro-tip and variable cutting edge geometry to guarantee maximum execution capacity. The step+ geometry spiral drill bit by Krino, on the other hand, is designed to highlight the quality of the hole. Above you can evaluate the difference in hole quality.

To read: how to countersink a hole

Coating of the most performing drill bits

HSS-Co drill bits with cobalt and molybdenum are perfect for withstanding mechanical and thermal stresses. With these tools you can easily drill stainless steel, tough and hard alloys. But there's an extra option for those who need drill bits that are increasingly more performing in terms of drilling: the TiAIN coating, namely titanium aluminum nitride.

This step gives toughness and hardness to the surface, resistance to high temperatures and corrosion resistance. So if you're looking for a dry, clean cut at the highest speed on resistant and abrasive steels you're in the right place: recognize drill bits treated with TiAIN by their bluish color. With these drill bits it will be easier to drill extremely hard metals without damaging the equipment and the base.